Video Stabilization and Wet Lenses

[Davide DB]

Naive question

 

For the past two years I have used almost exclusively the anonymous Lumix 14-42 mm lens coupled with the Nauticam WWL-1. Lately I have had a chance to reuse the Lumix 12-35 mm and 6" Nauticam dome and I noticed that the stabilization of my GH5M2 is much less effective with the 14-42 mm + WWL combo.

 

Could it be because the WWL alters the focal length of the lens a lot?

 

For manual lenses, the GH5 allows you to set the focal length manually, which serves precisely the stabilization algorithm.

 

 

[Guest]

You mean the 12-35mm lens is better?

I would say it is down to the lens OIS being better in general not an effect of the WWL-1

[Davide DB]

 

Yes, at the same focal length is significantly more stable. Then I made some test on land and there's no noticeable difference between them.

My speculation is the focal length it's part of the OIS algorithm. I don't see other reasons because you have to set it manually on  manual lenses. 

The 14-42 mm @14 has a FOV of 94° while behind the WWL become 130° so I am tricking the algorithm somehow.
 

 

[Guest]

2 hours ago, Davide DB said:

 

Yes, at the same focal length is significantly more stable. Then I made some test on land and there's no noticeable difference between them.

My speculation is the focal length it's part of the OIS algorithm. I don't see other reasons because you have to set it manually on  manual lenses. 

The 14-42 mm @14 has a FOV of 94° while behind the WWL become 130° so I am tricking the algorithm somehow.
 

 

14mm has a field of view of 75 degree only and the WWL-1 is distorted it is not 130 degrees more like 95 equivalent

There was some advice from nauticam to set this differently however because this is a zoom to what exactly you want to set it?

 

[Davide DB]

19 minutes ago, Interceptor121 said:

14mm has a field of view of 75 degree only and the WWL-1 is distorted it is not 130 degrees more like 95 equivalent

There was some advice from nauticam to set this differently however because this is a zoom to what exactly you want to set it?

 

 

Yes I was remembering incorrectly: its FOV is  74.8 - 28.6°. 

The explanation I gave myself is that the 12-35 behind the dome keeps more or less the same FOV while the WWL changes in FOV significantly confusing the algorithm.
Zoom or not you have no way to change the data with a native lens. I should check it again but IIRC The settings are disabled.

[Guest]

On 3/11/2024 at 11:52 AM, Davide DB said:

 

Yes I was remembering incorrectly: its FOV is  74.8 - 28.6°. 

The explanation I gave myself is that the 12-35 behind the dome keeps more or less the same FOV while the WWL changes in FOV significantly confusing the algorithm.
Zoom or not you have no way to change the data with a native lens. I should check it again but IIRC The settings are disabled.

Interesting I can override this on Sony the next question is to what though?

[Chris Ross]

Probably little you could do about it unless you could get the lens to report the focal length with the WWL.  That's probably something around a  14mm rectilinear frame (full frame equivalent) on the horizontal axis.    You could probably only tell by trying it and see how it handled.

[Davide DB]

1 hour ago, Chris Ross said:

Probably little you could do about it unless you could get the lens to report the focal length with the WWL.  That's probably something around a  14mm rectilinear frame (full frame equivalent) on the horizontal axis.    You could probably only tell by trying it and see how it handled.

 

Yes, I know.

I was asking to know if other people had noticed these differences in the water. On land there are not. Hence the explanation I gave myself.

Maybe with a prime lens I could even fool the algorithm, but with a zoom there's no way.

 

Thanks

 

[Guest]

1 hour ago, Davide DB said:

 

Yes, I know.

I was asking to know if other people had noticed these differences in the water. On land there are not. Hence the explanation I gave myself.

Maybe with a prime lens I could even fool the algorithm, but with a zoom there's no way.

 

Thanks

 

I recall backscatter suggesting to override this value. I need to find this article

[Guest]

2 hours ago, Davide DB said:

 

Yes, I know.

I was asking to know if other people had noticed these differences in the water. On land there are not. Hence the explanation I gave myself.

Maybe with a prime lens I could even fool the algorithm, but with a zoom there's no way.

 

Thanks

 

I have the 28mm prime I can try it with the WWL-1 and set to 20mm instead

 

Consider that Sony does not have lens stabilisation is only IBIS so maybe different

[Davide DB]

I am reopening this old thread because this WE I had the opportunity to reuse my Pana 12-35mm with 6” dome. As much as 12mm (24 FF equivalent) is indeed too narrow for panoramic shots, it turns out to be a killer lens for medium and narrow field shots. the lens is razor sharp. At the same focal length it is much more defined than the 14-42mm + WWL-1B.

 

But returning to the subject of the topic, I confirm that IBIS is completely confused by the FOV change made by WWL-1B. Shooting with the 12-35mm even at 35mm (70mm equiv. FF) is rock steady while my shots with the WWL always have a strange “sway”. In some shots it is almost imperceptible but it is there.

 

Looking back at all my shots taken with the WWL over the years I was in despair: with experience instead of getting better, I was getting worse. Reusing the 12-35mm was a pleasant experience.